MATLAB: How to create C library (‘.lib’ file) from the model in Real-Time Workshop 6.6 (R2007a)

ertlibrarieslibrarysimulink coderstatic

I would like to be able to create C library ('.lib' file) from my model. Using 'ert_shrlib.tlc' target, it is possible to create shared library (.dll files). I would like to know if it is possible to generate a '.lib' file too.

Best Answer

While using the shared library target 'ert_shrlib.tlc', by default '.lib' files are not created. However, you can change the default behavior and retain the '.lib' file by modifying the corresponding template makefile (TMF). For example in the template make file 'ert_vc.tmf' line 347 mentions that:

"#--- Comment out the next line to retain .lib and .exp files ---"

If you comment out the next line in this file, '.lib' and '.exp' files are retained. However, please note that if you do this, the generated 'model.h' file will need a small modification to be used together with the generated 'ert_main.c' for implicit linking. For example, if you are using the Microsoft Visual C++ development system, you will need to declare' __declspec(dllimport)' in front of all data to be imported implicitly from the shared library file.

This is also mentioned in the document. Please run the following command in MATLAB to see the documentation for this:

web([docroot,'/toolbox/ecoder/ug/bq2nslk-1.html#bq2nufb-1'])

Related Solutions

MATLAB: How to call a DLL created from Simulink model in a Visual Studio application

The TMF file that the documentation refers is the TMF file for the compiler that you have set. Suppose you are using Visual C compiler, you can find the actual tmf file under the following directory:

~matlabroot/rtw/c/ert/ert_vc.tmf

Where 'matlabroot' is the installation directory of your version of MATLAB.

In this file, search for the following section:

 #--- Comment out the next line to retain .lib and .exp files ---
 @del $(RELATIVE_PATH_TO_ANCHOR)\$(MODEL)_win32.lib
 $(RELATIVE_PATH_TO_ANCHOR)\$(MODEL)_win32.exp

As indicated above, if you comment out this section it should retain the '.lib' file.

For the point about modifying the header files:

There are two ways using DLLs:

1. Explicit : This way of using DLLs is demonstrated in the demo named 'rtwdemo_shrlib.mdl' and related examples. This way of linking is more portable (DLL are compiler independent, LIB are compiler dependent)

2. Implicit : Keep the import library LIB file and link against this LIB file. For MS VC, it is required to have every Symbol that would be in such imported library to be decorated with __declspec(dllimport) so that the user's application(caller of the functions in dll) , which should #include a header file that describes the DLL modules/data, can find the correct symbol in the DLL. The aforementioned header file can be derived from our generated model.h but must be modified as document stated.

A simple example:

In the model.h

 extern void nestedop_step(void);

shall be changed as in the modified header

__declspec(dllimport)  void nestedop_step(void);

This usage is more on the caller of the DLL side thus we would recommend the user to check examples on Microsoft website about how to call a function in DLL.

 <http://msdn.microsoft.com/en-us/library/3y1sfaz2(VS.80).aspx>

MATLAB: How to use the generated code from Real-Time Workshop 5.0 (R13) or 5.1 (R13SP1) in a cross-platform development environment

This change has been incorporated into the documentation in Release 14 Service Pack 3 (R14SP3). For previous releases, read below for any additional information:

Here is the recommended procedure for using Real-Time Workshop 5.0 (R13) or 5.1 (R13SP1) in a cross-platform development environment. These steps describe the process for the GRT target, but can be adapted to use the ERT target as well.

Note that if you are using Real-Time Workshop 6.1 (R14SP1), see the Related Solution listed at the bottom of the page.

Steps 1 and 2 are configuration steps which you only need to do once.

1. Create the requisite MATLAB tree on the UNIX machine with the source files necessary to compile RTW programs. Copy the following directories from the PC MATLAB installation onto your UNIX machine. (Note: These paths include the source code necessary for Simulink library blocks only.)

 simulink/include 
 extern/include 
 rtw/c/grt 
 rtw/c/libsrc 
 rtw/c/src 
 rtw/c/tools

For the purposes of this example, we will assume you installed these files in a directory called:

     /home/rtwuser/cross

NOTE: Your make utility and compiler may be sensitive to DOS/UNIX end-of-line character differences. We recommend you also run a dos2unix file conversion utility to ensure your files have UNIX end-of-line characters.

2. Create a cross-platform template makefile on your PC. On the PC, browse to the directory

     $MATLABROOT\rtw\c\grt 
     (where $MATLABROOT = the MATLAB root directory on your machine)

Make a copy of the file grt_unix.tmf and name it grt_cross.tmf.

3. On the platform that you will be cross-developing on, run the COMPUTER function in MATLAB.

computer

Take the result of that command and use that value from COMPUTER in the token line. You can also type

help computer

in your PC MATLAB session for a list of legal values. For the purposes of this example, we will assume the cross-development platform is 'SOL2' (Solaris).

4. Open grt_cross.tmf in the MATLAB editor or a text editor so that you can make some changes.

5. Change token line in grt_cross.tmf.

From:

MATLAB_ROOT          = |>MATLAB_ROOT<|

To:

MATLAB_ROOT          = /home/rtwuser/cross

6. Change token line in grt_cross.tmf:

From:

COMPUTER             = |>COMPUTER<|

To:

COMPUTER             = SOL2

NOTE: This is assuming the cross-development platform is 'SOL2' (Solaris). This change will hard-code the template makefile to use /home/rtwuser/cross as your MATLAB tree and also hard-codes the template makefile to build on a Solaris machine.

7. Change the following lines to hard-code the makefile to build rtwlib.a.

From:

ifeq ($(OPT_OPTS),$(DEFAULT_OPT_OPTS))
RTWLIB = $(MATLAB_ROOT)/rtw/c/lib/$(ARCH)/rtwlib_std.a
else
RTWLIB  = rtwlib.a
endif

To:

#ifeq ($(OPT_OPTS),$(DEFAULT_OPT_OPTS))
#RTWLIB = $(MATLAB_ROOT)/rtw/c/lib/$(ARCH)/rtwlib_std.a
#else
RTWLIB  = rtwlib.a
#endif

8. Change the following lines of code under Additional Libraries:

From:

LIBS =
|>START_PRECOMP_LIBRARIES<|
ifeq ($(OPT_OPTS),$(DEFAULT_OPT_OPTS))
LIBS += |>EXPAND_LIBRARY_LOCATION<|/|>EXPAND_LIBRARY_NAME<|_std.a
else
LIBS += |>EXPAND_LIBRARY_NAME<|.a
endif
|>END_PRECOMP_LIBRARIES<| |>START_EXPAND_LIBRARIES<|
LIBS += |>EXPAND_LIBRARY_NAME<|.a |>END_EXPAND_LIBRARIES<|
LIBS += $(S_FUNCTIONS_LIB) $(INSTRUMENT_LIBS)

To:

LIBS =
|>START_PRECOMP_LIBRARIES<|
LIBS += |>EXPAND_LIBRARY_NAME<|.a
|>END_PRECOMP_LIBRARIES<| |>START_EXPAND_LIBRARIES<|
LIBS += |>EXPAND_LIBRARY_NAME<|.a |>END_EXPAND_LIBRARIES<|
LIBS += $(S_FUNCTIONS_LIB) $(INSTRUMENT_LIBS)

NOTE: If you are using the ERT target, there will be a few additional lines of code in the section to be removed.

9. On the PC, open your Simulink model and open the Simulation Parameters, Real-Time Workshop tab. Change the template makefile to be 'grt_cross.tmf'.

10. Click the 'Build' button to generate code from your model. You should see RTW generate code and a makefile, but not build the executable.

11. Copy the files from the build directory on your PC to your UNIX working directory:

rtw_proj.tmw

model.h

model_prm.h

model_export.h

model.c

model.mk

model_reg.h

model_common.h

NOTE: Your make of utility and compiler may be sensitive to DOS/UNIX end-of-line character differences. We recommend you also run a dos2unix file conversion utility to ensure your files have UNIX end-of-line characters.

12. In UNIX, browse to the working directory where you copied the RTW model code from step 11.

13. Type the following at your UNIX prompt to build the model:

make -f model.mk

NOTE: You may receive one of the following errors if you did not run a dos2unix utility:

ERROR 1:

 make -f vdp.mk 
 : No such file or directory 
 vdp.mk:92: *** commands commence before first target. Stop.

Remedy: run dos2unix utility to conform to UNIX end-of-line character on the files you copied in step 11.

ERROR 2:

 make -f vdp.mk 
 cc -c -o 
 vdp.o -O -DMODEL=vdp -DRT -DNUMST=2 -DTID01EQ=1 -DNCSTATES=2 -DUNIX -DMT= 
 0 -I. -I/home/rtwuser/cross/simulink/include -I/home/rtwuser/cross/extern/in 
 clude -I/home/rtwuser/cross/rtw/c/src -I/home/rtwuser/cross/rtw/c/libsrc 
 vdp.c 
 "/home/rtwuser/cross/simulink/include/simstruc.h", line 47: warning: invalid 
 white space character in directive 
 "/home/rtwuser/cross/simulink/include/simstruc.h", line 48: warning: invalid white

Remedy: This can occur if you did not follow the instructions at the end of step 1. You need to run a dos2unix utility to conform to UNIX end-of-line characters on the files you copied in step 1.

Best Answer

Related Solutions

MATLAB: How to call a DLL created from Simulink model in a Visual Studio application

MATLAB: How to use the generated code from Real-Time Workshop 5.0 (R13) or 5.1 (R13SP1) in a cross-platform development environment

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